[PATCH v4 0/5] RZ/N1 RTC support

[PATCH v4 0/5] RZ/N1 RTC support

[Miquel Raynal]

Hello,

This small series adds support for the RZ/N1 RTC.

Despite its limitations, I found useful to at least have alarm and
offset support.

The RTC hclk fix has been merged in the renesas-clk-for-v5.19 branch so
I dropped it from the series. Same for the DT patch.

Cheers,
Miquèl

Changes in v4:
* Collected more tags (on the DT bindings).
* Fixed the name of the SoC in the header: RZ/N1 instead of RZN1.
* Dropped the error message when the alarm IRQ is not available (already
  handled by the core)
* Used pm_runtime_put() instead of pm_runtime_put_sync().
* Used pm_runtime_resume_and_get() instead of pm_runtime_get().
* Used devm_pm_runtime_enable() instead of pm_runtime_enable().

Changes in v3:
* Collected tags.
* s/soc:/clk:/ in the clock commit title.
* Dropped the RTC hclk fix which has already been applied.
* Added the power-domain properties both in the bindings and in the DT.
* Used runtime PM to enable the clock instead of using the clk API
  directly. 

Changes in v2:
* Fixed the error path in the clk driver, where I missed to release a
  spin_lock.
* Collected tags.
* Moved the rtc subnode in the dt to keep the nodes ordered by unit
  address.
* Dropped the useless "oneOf" statement in the bindings (compatible
  property).
* Dropped the start-year property in the bindings (already defined).
* Avoided rollover calculations that could be more easily handled (and
  reviewed) with a time64_t conversion.
* Returned ERANGE instead of EOPNOTSUPP when the alarm date is not
  valid.
* Cleared RTC_FEATURE_UPDATE_INTERRUPT to avoid warning from the tools.
* Dropped the sysctl patch adding the reset helper, instead fulfilled
  the description of the RTC clock so that when requesting this clock to
  be enabled, the idle bit is released.
* Avoided rollover calculations that could be more easily handled
  (and reviewed) with a time64_t conversion.
* Fixed the max_range value, after a rtc-range test and looking at other
  implementations.

Michel Pollet (1):
  rtc: rzn1: Add new RTC driver

Miquel Raynal (4):
  dt-bindings: rtc: rzn1: Describe the RZN1 RTC
  rtc: rzn1: Add alarm support
  rtc: rzn1: Add oscillator offset support
  MAINTAINERS: Add myself as maintainer of the RZN1 RTC driver

 .../bindings/rtc/renesas,rzn1-rtc.yaml        |  70 +++
 MAINTAINERS                                   |   8 +
 drivers/rtc/Kconfig                           |   7 +
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-rzn1.c                        | 423 ++++++++++++++++++
 5 files changed, 509 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml
 create mode 100644 drivers/rtc/rtc-rzn1.c

-- 
2.27.0

[PATCH v4 1/5] dt-bindings: rtc: rzn1: Describe the RZN1 RTC

[Miquel Raynal]

Add new binding file for this RTC.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 .../bindings/rtc/renesas,rzn1-rtc.yaml        | 70 +++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml

diff --git a/Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml b/Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml
new file mode 100644
index 000000000000..2d4741f51663
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/renesas,rzn1-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/N1 SoCs Real-Time Clock DT bindings
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - renesas,r9a06g032-rtc
+      - const: renesas,rzn1-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 3
+    maxItems: 3
+
+  interrupt-names:
+    items:
+      - const: alarm
+      - const: timer
+      - const: pps
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: hclk
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+  - power-domains
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/r9a06g032-sysctrl.h>
+    rtc@40006000 {
+       compatible = "renesas,r9a06g032-rtc", "renesas,rzn1-rtc";
+       reg = <0x40006000 0x1000>;
+       interrupts = <GIC_SPI 66 IRQ_TYPE_EDGE_RISING>,
+                    <GIC_SPI 67 IRQ_TYPE_EDGE_RISING>,
+                    <GIC_SPI 68 IRQ_TYPE_EDGE_RISING>;
+       interrupt-names = "alarm", "timer", "pps";
+       clocks = <&sysctrl R9A06G032_HCLK_RTC>;
+       clock-names = "hclk";
+       power-domains = <&sysctrl>;
+       start-year = <2000>;
+     };
-- 
2.27.0

[PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Miquel Raynal]

From: Michel Pollet <michel.pollet@bp.renesas.com>

Add a basic RTC driver for the RZ/N1.

Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/rtc/Kconfig    |   7 ++
 drivers/rtc/Makefile   |   1 +
 drivers/rtc/rtc-rzn1.c | 246 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 254 insertions(+)
 create mode 100644 drivers/rtc/rtc-rzn1.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 41c65b4d2baf..a00f901b5c1d 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1548,6 +1548,13 @@ config RTC_DRV_RS5C313
 	help
 	  If you say yes here you get support for the Ricoh RS5C313 RTC chips.
 
+config RTC_DRV_RZN1
+	tristate "Renesas RZ/N1 RTC"
+	depends on ARCH_RZN1 || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  If you say yes here you get support for the Renesas RZ/N1 RTC.
+
 config RTC_DRV_GENERIC
 	tristate "Generic RTC support"
 	# Please consider writing a new RTC driver instead of using the generic
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 2d827d8261d5..fb04467b652d 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -151,6 +151,7 @@ obj-$(CONFIG_RTC_DRV_RX6110)	+= rtc-rx6110.o
 obj-$(CONFIG_RTC_DRV_RX8010)	+= rtc-rx8010.o
 obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
 obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
+obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
 obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
 obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
 obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
new file mode 100644
index 000000000000..1d4e7a782749
--- /dev/null
+++ b/drivers/rtc/rtc-rzn1.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Renesas RZ/N1 Real Time Clock interface for Linux
+ *
+ * Copyright:
+ * - 2014 Renesas Electronics Europe Limited
+ * - 2022 Schneider Electric
+ *
+ * Authors:
+ * - Michel Pollet <michel.pollet@bp.renesas.com>, <buserror@gmail.com>
+ * - Miquel Raynal <miquel.raynal@bootlin.com>
+ */
+
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/rtc.h>
+#include <linux/soc/renesas/r9a06g032-sysctrl.h>
+
+#define RZN1_RTC_CTL0 0x00
+#define   RZN1_RTC_CTL0_SLSB_SUBU 0
+#define   RZN1_RTC_CTL0_SLSB_SCMP BIT(4)
+#define   RZN1_RTC_CTL0_AMPM BIT(5)
+#define   RZN1_RTC_CTL0_CE BIT(7)
+
+#define RZN1_RTC_CTL1 0x04
+#define   RZN1_RTC_CTL1_ALME BIT(4)
+
+#define RZN1_RTC_CTL2 0x08
+#define   RZN1_RTC_CTL2_WAIT BIT(0)
+#define   RZN1_RTC_CTL2_WST BIT(1)
+#define   RZN1_RTC_CTL2_WUST BIT(5)
+#define   RZN1_RTC_CTL2_STOPPED (RZN1_RTC_CTL2_WAIT | RZN1_RTC_CTL2_WST)
+
+#define RZN1_RTC_SEC 0x14
+#define RZN1_RTC_MIN 0x18
+#define RZN1_RTC_HOUR 0x1c
+#define RZN1_RTC_WEEK 0x20
+#define RZN1_RTC_DAY 0x24
+#define RZN1_RTC_MONTH 0x28
+#define RZN1_RTC_YEAR 0x2c
+
+#define RZN1_RTC_SUBU 0x38
+#define   RZN1_RTC_SUBU_DEV BIT(7)
+#define   RZN1_RTC_SUBU_DECR BIT(6)
+
+#define RZN1_RTC_ALM 0x40
+#define RZN1_RTC_ALH 0x44
+#define RZN1_RTC_ALW 0x48
+
+#define RZN1_RTC_SECC 0x4c
+#define RZN1_RTC_MINC 0x50
+#define RZN1_RTC_HOURC 0x54
+#define RZN1_RTC_WEEKC 0x58
+#define RZN1_RTC_DAYC 0x5c
+#define RZN1_RTC_MONTHC 0x60
+#define RZN1_RTC_YEARC 0x64
+
+struct rzn1_rtc {
+	struct rtc_device *rtcdev;
+	void __iomem *base;
+	struct clk *clk;
+};
+
+static void rzn1_rtc_get_time_snapshot(struct rzn1_rtc *rtc, struct rtc_time *tm)
+{
+	tm->tm_sec = readl(rtc->base + RZN1_RTC_SECC);
+	tm->tm_min = readl(rtc->base + RZN1_RTC_MINC);
+	tm->tm_hour = readl(rtc->base + RZN1_RTC_HOURC);
+	tm->tm_wday = readl(rtc->base + RZN1_RTC_WEEKC);
+	tm->tm_mday = readl(rtc->base + RZN1_RTC_DAYC);
+	tm->tm_mon = readl(rtc->base + RZN1_RTC_MONTHC);
+	tm->tm_year = readl(rtc->base + RZN1_RTC_YEARC);
+}
+
+static unsigned int rzn1_rtc_tm_to_wday(struct rtc_time *tm)
+{
+	time64_t time;
+	unsigned int days;
+	u32 secs;
+
+	time = rtc_tm_to_time64(tm);
+	days = div_s64_rem(time, 86400, &secs);
+
+	/* day of the week, 1970-01-01 was a Thursday */
+	return (days + 4) % 7;
+}
+
+static int rzn1_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 val, secs;
+
+	/*
+	 * The RTC was not started or is stopped and thus does not carry the
+	 * proper time/date.
+	 */
+	val = readl(rtc->base + RZN1_RTC_CTL2);
+	if (val & RZN1_RTC_CTL2_STOPPED)
+		return -EINVAL;
+
+	rzn1_rtc_get_time_snapshot(rtc, tm);
+	secs = readl(rtc->base + RZN1_RTC_SECC);
+	if (tm->tm_sec != secs)
+		rzn1_rtc_get_time_snapshot(rtc, tm);
+
+	tm->tm_sec = bcd2bin(tm->tm_sec);
+	tm->tm_min = bcd2bin(tm->tm_min);
+	tm->tm_hour = bcd2bin(tm->tm_hour);
+	tm->tm_wday = bcd2bin(tm->tm_wday);
+	tm->tm_mday = bcd2bin(tm->tm_mday);
+	tm->tm_mon = bcd2bin(tm->tm_mon);
+	tm->tm_year = bcd2bin(tm->tm_year);
+
+	return 0;
+}
+
+static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 val;
+	int ret;
+
+	tm->tm_sec = bin2bcd(tm->tm_sec);
+	tm->tm_min = bin2bcd(tm->tm_min);
+	tm->tm_hour = bin2bcd(tm->tm_hour);
+	tm->tm_wday = bin2bcd(rzn1_rtc_tm_to_wday(tm));
+	tm->tm_mday = bin2bcd(tm->tm_mday);
+	tm->tm_mon = bin2bcd(tm->tm_mon);
+	tm->tm_year = bin2bcd(tm->tm_year);
+
+	val = readl(rtc->base + RZN1_RTC_CTL2);
+	if (!(val & RZN1_RTC_CTL2_STOPPED)) {
+		/* Hold the counter if it was counting up */
+		writel(RZN1_RTC_CTL2_WAIT, rtc->base + RZN1_RTC_CTL2);
+
+		/* Wait for the counter to stop: two 32k clock cycles */
+		usleep_range(61, 100);
+		ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val,
+					 val & RZN1_RTC_CTL2_WST, 0, 100);
+		if (ret)
+			return ret;
+	}
+
+	writel(tm->tm_sec, rtc->base + RZN1_RTC_SEC);
+	writel(tm->tm_min, rtc->base + RZN1_RTC_MIN);
+	writel(tm->tm_hour, rtc->base + RZN1_RTC_HOUR);
+	writel(tm->tm_wday, rtc->base + RZN1_RTC_WEEK);
+	writel(tm->tm_mday, rtc->base + RZN1_RTC_DAY);
+	writel(tm->tm_mon, rtc->base + RZN1_RTC_MONTH);
+	writel(tm->tm_year, rtc->base + RZN1_RTC_YEAR);
+	writel(0, rtc->base + RZN1_RTC_CTL2);
+
+	return 0;
+}
+
+static const struct rtc_class_ops rzn1_rtc_ops = {
+	.read_time = rzn1_rtc_read_time,
+	.set_time = rzn1_rtc_set_time,
+};
+
+static int rzn1_rtc_probe(struct platform_device *pdev)
+{
+	struct rzn1_rtc *rtc;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(rtc->base))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n");
+
+	rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtcdev))
+		return PTR_ERR(rtc);
+
+	rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
+	rtc->rtcdev->ops = &rzn1_rtc_ops;
+	clear_bit(RTC_FEATURE_ALARM, rtc->rtcdev->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features);
+
+	devm_pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Ensure the clock counter is enabled.
+	 * Set 24-hour mode and possible oscillator offset compensation in SUBU mode.
+	 */
+	writel(RZN1_RTC_CTL0_CE | RZN1_RTC_CTL0_AMPM | RZN1_RTC_CTL0_SLSB_SUBU,
+	       rtc->base + RZN1_RTC_CTL0);
+
+	/* Disable all interrupts */
+	writel(0, rtc->base + RZN1_RTC_CTL1);
+
+	ret = devm_rtc_register_device(rtc->rtcdev);
+	if (ret)
+		goto dis_runtime_pm;
+
+	return 0;
+
+dis_runtime_pm:
+	pm_runtime_put(&pdev->dev);
+
+	return ret;
+}
+
+static int rzn1_rtc_remove(struct platform_device *pdev)
+{
+	pm_runtime_put(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id rzn1_rtc_of_match[] = {
+	{ .compatible	= "renesas,rzn1-rtc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rzn1_rtc_of_match);
+
+static struct platform_driver rzn1_rtc_driver = {
+	.probe = rzn1_rtc_probe,
+	.remove = rzn1_rtc_remove,
+	.driver = {
+		.name	= "rzn1-rtc",
+		.owner	= THIS_MODULE,
+		.of_match_table = rzn1_rtc_of_match,
+	},
+};
+module_platform_driver(rzn1_rtc_driver);
+
+MODULE_AUTHOR("Michel Pollet <Michel.Pollet@bp.renesas.com");
+MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
+MODULE_DESCRIPTION("RZ/N1 RTC driver");
+MODULE_LICENSE("GPL");
-- 
2.27.0

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[kernel test robot]

Hi Miquel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on abelloni/rtc-next]
[also build test ERROR on robh/for-next linus/master v5.18-rc6 next-20220509]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Miquel-Raynal/RZ-N1-RTC-support/20220509-235039
base:   https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20220510/202205100552.VY3kCkh5-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/c3fe09f9df58326a1b888fce48df245964362348
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Miquel-Raynal/RZ-N1-RTC-support/20220509-235039
        git checkout c3fe09f9df58326a1b888fce48df245964362348
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory
      23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   compilation terminated.


vim +23 drivers/rtc/rtc-rzn1.c

  > 23	#include <linux/soc/renesas/r9a06g032-sysctrl.h>
    24	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Miquel Raynal]

Hi Alex,

lkp@intel.com wrote on Tue, 10 May 2022 05:26:55 +0800:

> Hi Miquel,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on abelloni/rtc-next]
> [also build test ERROR on robh/for-next linus/master v5.18-rc6 next-20220509]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 

[...]

> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
> >> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory  
>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    compilation terminated.

That include is no longer needed in this driver (and should be merged
through another tree). Tell me if I need to resend or if you can fix it
while applying.

Thanks,
Miquèl

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Miquel Raynal]

[-- Attachment #1: Type: text/plain, Size: 1105 bytes --]

Hi Alex,

lkp(a)intel.com wrote on Tue, 10 May 2022 05:26:55 +0800:

> Hi Miquel,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on abelloni/rtc-next]
> [also build test ERROR on robh/for-next linus/master v5.18-rc6 next-20220509]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 

[...]

> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
> >> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory  
>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    compilation terminated.

That include is no longer needed in this driver (and should be merged
through another tree). Tell me if I need to resend or if you can fix it
while applying.

Thanks,
Miquèl

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Krzysztof Kozlowski]

On 10/05/2022 09:29, Miquel Raynal wrote:
> 
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <lkp@intel.com>
>>
>> All errors (new ones prefixed by >>):
>>
>>>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory  
>>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
>>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>    compilation terminated.
> 
> That include is no longer needed in this driver (and should be merged
> through another tree). Tell me if I need to resend or if you can fix it
> while applying.

This should be resent so we are sure that no other warnings are reported.

Best regards,
Krzysztof

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Krzysztof Kozlowski]

[-- Attachment #1: Type: text/plain, Size: 763 bytes --]

On 10/05/2022 09:29, Miquel Raynal wrote:
> 
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <lkp@intel.com>
>>
>> All errors (new ones prefixed by >>):
>>
>>>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory  
>>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
>>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>    compilation terminated.
> 
> That include is no longer needed in this driver (and should be merged
> through another tree). Tell me if I need to resend or if you can fix it
> while applying.

This should be resent so we are sure that no other warnings are reported.

Best regards,
Krzysztof

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Miquel Raynal]

Hi Krzysztof,

krzysztof.kozlowski@linaro.org wrote on Tue, 10 May 2022 12:06:39 +0200:

> On 10/05/2022 09:29, Miquel Raynal wrote:
> >   
> >> If you fix the issue, kindly add following tag as appropriate
> >> Reported-by: kernel test robot <lkp@intel.com>
> >>
> >> All errors (new ones prefixed by >>):
> >>  
> >>>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory    
> >>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
> >>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>    compilation terminated.  
> > 
> > That include is no longer needed in this driver (and should be merged
> > through another tree). Tell me if I need to resend or if you can fix it
> > while applying.  
> 
> This should be resent so we are sure that no other warnings are reported.

Ok, I'll edit the file and resend.

Thanks,
Miquèl

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[Miquel Raynal]

[-- Attachment #1: Type: text/plain, Size: 932 bytes --]

Hi Krzysztof,

krzysztof.kozlowski(a)linaro.org wrote on Tue, 10 May 2022 12:06:39 +0200:

> On 10/05/2022 09:29, Miquel Raynal wrote:
> >   
> >> If you fix the issue, kindly add following tag as appropriate
> >> Reported-by: kernel test robot <lkp@intel.com>
> >>
> >> All errors (new ones prefixed by >>):
> >>  
> >>>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: linux/soc/renesas/r9a06g032-sysctrl.h: No such file or directory    
> >>       23 | #include <linux/soc/renesas/r9a06g032-sysctrl.h>
> >>          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>    compilation terminated.  
> > 
> > That include is no longer needed in this driver (and should be merged
> > through another tree). Tell me if I need to resend or if you can fix it
> > while applying.  
> 
> This should be resent so we are sure that no other warnings are reported.

Ok, I'll edit the file and resend.

Thanks,
Miquèl

Re: [PATCH v4 2/5] rtc: rzn1: Add new RTC driver

[kernel test robot]

Hi Miquel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on abelloni/rtc-next]
[also build test ERROR on robh/for-next linus/master v5.18-rc6 next-20220509]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Miquel-Raynal/RZ-N1-RTC-support/20220509-235039
base:   https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20220510/202205101957.jVrQugEU-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 3abb68a626160e019c30a4860e569d7bc75e486a)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/c3fe09f9df58326a1b888fce48df245964362348
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Miquel-Raynal/RZ-N1-RTC-support/20220509-235039
        git checkout c3fe09f9df58326a1b888fce48df245964362348
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kernel/ drivers/rtc/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/rtc/rtc-rzn1.c:23:10: fatal error: 'linux/soc/renesas/r9a06g032-sysctrl.h' file not found
   #include <linux/soc/renesas/r9a06g032-sysctrl.h>
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1 error generated.


vim +23 drivers/rtc/rtc-rzn1.c

  > 23	#include <linux/soc/renesas/r9a06g032-sysctrl.h>
    24	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

[PATCH v4 3/5] rtc: rzn1: Add alarm support

[Miquel Raynal]

The RZN1 RTC can trigger an interrupt when reaching a particular date up
to 7 days ahead. Bring support for this alarm.

One drawback though, the granularity is about a minute.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/rtc/rtc-rzn1.c | 106 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 105 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
index 1d4e7a782749..7e0609ac8aa8 100644
--- a/drivers/rtc/rtc-rzn1.c
+++ b/drivers/rtc/rtc-rzn1.c
@@ -159,14 +159,107 @@ static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	return 0;
 }
 
+static irqreturn_t rzn1_rtc_alarm_irq(int irq, void *dev_id)
+{
+	struct rzn1_rtc *rtc = dev_id;
+
+	rtc_update_irq(rtc->rtcdev, 1, RTC_AF | RTC_IRQF);
+
+	return IRQ_HANDLED;
+}
+
+static int rzn1_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 ctl1 = readl(rtc->base + RZN1_RTC_CTL1);
+
+	if (enable)
+		ctl1 |= RZN1_RTC_CTL1_ALME;
+	else
+		ctl1 &= ~RZN1_RTC_CTL1_ALME;
+
+	writel(ctl1, rtc->base + RZN1_RTC_CTL1);
+
+	return 0;
+}
+
+static int rzn1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time;
+	unsigned int min, hour, wday, delta_days;
+	time64_t alarm;
+	u32 ctl1;
+	int ret;
+
+	ret = rzn1_rtc_read_time(dev, tm);
+	if (ret)
+		return ret;
+
+	min = readl(rtc->base + RZN1_RTC_ALM);
+	hour = readl(rtc->base + RZN1_RTC_ALH);
+	wday = readl(rtc->base + RZN1_RTC_ALW);
+
+	tm->tm_sec = 0;
+	tm->tm_min = bcd2bin(min);
+	tm->tm_hour = bcd2bin(hour);
+	delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7;
+	tm->tm_wday = fls(wday) - 1;
+
+	if (delta_days) {
+		alarm = rtc_tm_to_time64(tm) + (delta_days * 86400);
+		rtc_time64_to_tm(alarm, tm);
+	}
+
+	ctl1 = readl(rtc->base + RZN1_RTC_CTL1);
+	alrm->enabled = !!(ctl1 & RZN1_RTC_CTL1_ALME);
+
+	return 0;
+}
+
+static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time, tm_now;
+	unsigned long alarm, farest;
+	unsigned int days_ahead, wday;
+	int ret;
+
+	ret = rzn1_rtc_read_time(dev, &tm_now);
+	if (ret)
+		return ret;
+
+	/* We cannot set alarms more than one week ahead */
+	farest = rtc_tm_to_time64(&tm_now) + (7 * 86400);
+	alarm = rtc_tm_to_time64(tm);
+	if (time_after(alarm, farest))
+		return -ERANGE;
+
+	/* Convert alarm day into week day */
+	days_ahead = tm->tm_mday - tm_now.tm_mday;
+	wday = (tm_now.tm_wday + days_ahead) % 7;
+
+	writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM);
+	writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH);
+	writel(BIT(wday), rtc->base + RZN1_RTC_ALW);
+
+	rzn1_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+	return 0;
+}
+
 static const struct rtc_class_ops rzn1_rtc_ops = {
 	.read_time = rzn1_rtc_read_time,
 	.set_time = rzn1_rtc_set_time,
+	.read_alarm = rzn1_rtc_read_alarm,
+	.set_alarm = rzn1_rtc_set_alarm,
+	.alarm_irq_enable = rzn1_rtc_alarm_irq_enable,
 };
 
 static int rzn1_rtc_probe(struct platform_device *pdev)
 {
 	struct rzn1_rtc *rtc;
+	int alarm_irq;
 	int ret;
 
 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
@@ -179,6 +272,10 @@ static int rzn1_rtc_probe(struct platform_device *pdev)
 	if (IS_ERR(rtc->base))
 		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n");
 
+	alarm_irq = platform_get_irq(pdev, 0);
+	if (alarm_irq < 0)
+		return alarm_irq;
+
 	rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
 	if (IS_ERR(rtc->rtcdev))
 		return PTR_ERR(rtc);
@@ -186,7 +283,7 @@ static int rzn1_rtc_probe(struct platform_device *pdev)
 	rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
 	rtc->rtcdev->ops = &rzn1_rtc_ops;
-	clear_bit(RTC_FEATURE_ALARM, rtc->rtcdev->features);
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtcdev->features);
 	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features);
 
 	devm_pm_runtime_enable(&pdev->dev);
@@ -204,6 +301,13 @@ static int rzn1_rtc_probe(struct platform_device *pdev)
 	/* Disable all interrupts */
 	writel(0, rtc->base + RZN1_RTC_CTL1);
 
+	ret = devm_request_irq(&pdev->dev, alarm_irq, rzn1_rtc_alarm_irq, 0,
+			       dev_name(&pdev->dev), rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "RTC timer interrupt not available\n");
+		goto dis_runtime_pm;
+	}
+
 	ret = devm_rtc_register_device(rtc->rtcdev);
 	if (ret)
 		goto dis_runtime_pm;
-- 
2.27.0

[PATCH v4 4/5] rtc: rzn1: Add oscillator offset support

[Miquel Raynal]

The RZN1 RTC can compensate the imprecision of the oscillator up to
approximately 190ppm.

Seconds can last slightly shorter or longer depending on the
configuration.

Below ~65ppm of correction, we can change the time spent in a second
every minute, which is the most accurate compensation that the RTC can
offer. Above, the compensation will be active every 20s.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/rtc/rtc-rzn1.c | 73 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
index 7e0609ac8aa8..0262689a823e 100644
--- a/drivers/rtc/rtc-rzn1.c
+++ b/drivers/rtc/rtc-rzn1.c
@@ -248,12 +248,85 @@ static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	return 0;
 }
 
+static int rzn1_rtc_read_offset(struct device *dev, long *offset)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	unsigned int ppb_per_step;
+	bool subtract;
+	u32 val;
+
+	val = readl(rtc->base + RZN1_RTC_SUBU);
+	ppb_per_step = val & RZN1_RTC_SUBU_DEV ? 1017 : 3051;
+	subtract = val & RZN1_RTC_SUBU_DECR;
+	val &= 0x3F;
+
+	if (!val)
+		*offset = 0;
+	else if (subtract)
+		*offset = -(((~val) & 0x3F) + 1) * ppb_per_step;
+	else
+		*offset = (val - 1) * ppb_per_step;
+
+	return 0;
+}
+
+static int rzn1_rtc_set_offset(struct device *dev, long offset)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	unsigned int steps, ppb_per_step;
+	int stepsh, stepsl;
+	u32 val;
+	int ret;
+
+	/*
+	 * Check which resolution mode (every 20 or 60s) can be used.
+	 * Between 2 and 124 clock pulses can be added or substracted.
+	 *
+	 * In 20s mode, the minimum resolution is 2 / (32768 * 20) which is
+	 * close to 3051 ppb. In 60s mode, the resolution is closer to 1017.
+	 */
+	stepsh = DIV_ROUND_CLOSEST(offset, 1017);
+	stepsl = DIV_ROUND_CLOSEST(offset, 3051);
+
+	if (stepsh >= -0x3E && stepsh <= 0x3E) {
+		ppb_per_step = 1017;
+		steps = stepsh;
+		val |= RZN1_RTC_SUBU_DEV;
+	} else if (stepsl >= -0x3E && stepsl <= 0x3E) {
+		ppb_per_step = 3051;
+		steps = stepsl;
+	} else {
+		return -ERANGE;
+	}
+
+	if (!steps)
+		return 0;
+
+	if (steps > 0) {
+		val |= steps + 1;
+	} else {
+		val |= RZN1_RTC_SUBU_DECR;
+		val |= (~(-steps - 1)) & 0x3F;
+	}
+
+	ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val,
+				 !(val & RZN1_RTC_CTL2_WUST), 100, 2000000);
+	if (ret)
+		return ret;
+
+	writel(val, rtc->base + RZN1_RTC_SUBU);
+
+	return 0;
+}
+
 static const struct rtc_class_ops rzn1_rtc_ops = {
 	.read_time = rzn1_rtc_read_time,
 	.set_time = rzn1_rtc_set_time,
 	.read_alarm = rzn1_rtc_read_alarm,
 	.set_alarm = rzn1_rtc_set_alarm,
 	.alarm_irq_enable = rzn1_rtc_alarm_irq_enable,
+	.read_offset = rzn1_rtc_read_offset,
+	.set_offset = rzn1_rtc_set_offset,
 };
 
 static int rzn1_rtc_probe(struct platform_device *pdev)
-- 
2.27.0

[PATCH v4 5/5] MAINTAINERS: Add myself as maintainer of the RZN1 RTC driver

[Miquel Raynal]

After contributing it, I'll volunteer to maintain it.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9cf74e4eacce..cc4a3cca022e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16847,6 +16847,14 @@ S:	Supported
 F:	Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml
 F:	drivers/iio/adc/rzg2l_adc.c
 
+RENESAS RZ/N1 RTC CONTROLLER DRIVER
+M:	Miquel Raynal <miquel.raynal@bootlin.com>
+L:	linux-rtc@vger.kernel.org
+L:	linux-renesas-soc@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml
+F:	drivers/rtc/rtc-rzn1.c
+
 RENESAS R-CAR GEN3 & RZ/N1 NAND CONTROLLER DRIVER
 M:	Miquel Raynal <miquel.raynal@bootlin.com>
 L:	linux-mtd@lists.infradead.org
-- 
2.27.0